WCAG 2.1 · Level AA · Perceivable
1.4.10 Reflow
Manual verification
How to validate 1.4.10 by hand
Check content reflow at the equivalent of 320 CSS pixels wide for vertically scrolling content and 256 CSS pixels high for horizontally scrolling content.
Start with the extension result
Reopen the reported URL and reproduce the same state (for example, after expanding a menu or submitting a form). Use the result’s Highlight action when available, or its affected-element details and CSS selector, to find the reported content. Apply the checks below to that content and its context. If the element or state has changed, rescan and record that difference before deciding whether the finding still applies.
- Set the viewport to the criterion’s equivalent dimensions or use 400 percent zoom on a 1280 CSS-pixel-wide viewport.
- Inspect text, controls, and ordinary content for two-dimensional scrolling, clipping, overlap, or loss of information.
- Check content that legitimately needs two-dimensional layout, such as data tables or maps, separately from the surrounding page.
Evidence to record
Record viewport/zoom, the content requiring two-dimensional scrolling, and whether that content qualifies for an exception.
Scope and exceptions
Some content needs two-dimensional layout to preserve meaning or use. A horizontal scrollbar alone is not a failure; evaluate the criterion’s exceptions and the page around that content.
Record the review outcome
- Confirmed: the recorded evidence shows the requirement is not met in the tested page state, and no applicable exception explains it.
- Not reproduced: the reported issue is absent in the current state. Record the URL, state, and affected element you checked; this does not prove other pages or states conform.
- Needs more review: evidence is incomplete, the content requires human judgment, or an exception is uncertain. Record what remains to be checked instead of treating it as a pass.